Flowable fill is commonly used as an economical fill or backfill in road construction. It is usually a mixture of coal fly ash, water, a coarse aggregate (such as sand), and portland cement. Flowable fill can take the place of concrete, compacted soils, or sand commonly used to fill around pipes or void areas. Other applications include filling in bridge abutments, foundation subbases, or abandoned man holes and wells. Flowable fill can help put significant quantities of coal fly ash and spent foundry sand, two types of recovered materials, back to good use.
- Recommended Recovered Materials Content Ranges
- Product Specifications
- Product Information
- Additional Links
EPA recommends that procuring agencies use flowable fill containing coal fly ash and/or ferrous foundry sands for backfill and other fill applications. Specific content levels will depend on the specifics of the job, including the type of coal fly ash (Class C or Class F) or foundry sand used, strength, set time, flowability needed, bleeding, and shrinkage. See a table showing typical proportions for high and low coal fly ash content mixtures.
- EPA recommends that procuring agencies use ACI229R-94
and the American Society for Testing and Materials (ASTM)
standards when purchasing flowable fill or contracting for
construction that involves backfilling or other fill
a list of recommended ASTM standards.
a list of states with specifications for flowable fill
containing coal fly ash.
- No national test methods or specifications exist for flowable fill mixtures containing foundry sand. Ohio has a specification entitled, "Flowable Fill Made With Spent Foundry Sand," however. In addition, Pennsylvania, Wisconsin, and Indiana are developing specifications.
of Manufacturers and Suppliers
This database identifies manufacturers and suppliers of flowable fill containing recovered materials.
Buy-Recycled Series: Construction Products (PDF) (11 pp, 104K, About PDF)
This fact sheet highlights construction products designated in the CPG, including flowable fill, and includes case studies, recommended recovered-content levels, and a list of resources.
This background document includes EPA's product research on recovered-content flowable fill as well as a more detailed overview of the history and regulatory requirements of the CPG process.